This application incorporates herein by reference Japanese Patent Application No. 2000-294458 filed Sep. 27, 2000.
The present invention relates to a remote vehicle monitoring system and a vehicle-mounted device therefor.
Various remote monitoring systems are proposed for monitoring stolen-vehicles at remote monitoring stations by the use of radio communication with vehicle-mounted car phones (mobile phones). For instance, in JP 2955702, a stolen-vehicle monitoring station transmits a call signal and a car phone of a stolen-vehicle automatically transmits a response signal including its present position information in response to the call signal.
However, the above radio communication between the monitoring station and the stolen-vehicle is disabled, if the car phone is kept used by an unauthorized user who stole the vehicle. The same problem occurs when the stolen-vehicle leaves away from a communication zone of the car phone. The monitoring station will have to continue to transmit a call signal, if a response from the car phone is desired immediately when the car phone becomes available again or the vehicle enters the communication zone of the car phone again.
It is therefore an object of the present invention to provide a remote vehicle monitoring system, which maximizes radio communications between a vehicle and a remote monitoring station.
According to the present invention, a vehicle monitoring system comprises a monitor station and a vehicle-mounted device, which perform radio communication therebetween. The vehicle-mounted device specifies its present position while in travel. When a vehicle theft occurs, the vehicle-mounted device interrupts on-going communication with an opponent when the opponent is other than the monitor station and connect to the monitor station for transmitting the present position of the stolen-vehicle.